REG NACA-RM-L8H20-1948 An investigation at low speed of a 51 3 degree sweptback semispan wing equipped with 16 7-percent-chord plain flaps and ailerons having various spans and thr.pdf

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1、Copy No. 2 711. FCM No. L8H20 RESEARCH MEMORANDUM- CIASSLBLCAT LON CdAtim LU UWJA3SIFIEB AUTHOHTP ChOPLEP CHANGE #2COa 4ATE G2-L4-53 T.C.F. 4 AN INVEsTIGATION AT LOW SPEED OF +-51.3-SWEpTRACK . . . SEMISPAN WING EQffIPPED WITH 16.7-PERCENT-CHORD w PLAIN FLAPS AND AILERONS HAVING VARIOUS SPANS AND TH

2、REE TRAILING-EDGE ANGLES Jack Fischel and Leslie E. Schneider Langley Aeronautical Laboratory Langley Field, Va. - NATIONAL ADVISORY COMMITTE-E . FOR AERONAUTICS WASHINGTON November 12, 1948 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NalmfW Aerm

3、auhca and Swce AdnuooValtm %mmAmol l39A To: DiaUibution I . -, JUN 1 UI993 PRoHa 18oA/8ecurity Cleaeificeticn Officer 8083EcT1 Authority to Dmhe6ify KACWN #AsA SciLentWic and Teobniorl InCormation raoilfty 1.0. box a757 Wn Airport, F 21240 . Provided by IHSNot for ResaleNo reproduction or networking

4、 permitted without license from IHS-,-,-N.KCIONALABVISOIIYCOMMWDEFORAERONAUTICS SEMISFAN WING EQiJEFLtD wmx 16 .FPER-KD PIADI - AXD AILERONS HATmG VARIOUS FzANsANDm -ANGm By Jack Fischel and Leelie E. Sps and ailerona having various spans f3nd spanwise locations, and with one apan of aileron having

5、trailing- edge angles of 6O, UP, ana. 25O. Lift, drag, pitching-mament, and flap hinge-moms also, in this angle-of-attack range, the spoiler aileron generally produced larger rolling moments wfth flap deflected than with flap undeflected. Provided by IHSNot for ResaleNo reproduction or networking pe

6、rmitted without license from IHS-,-,-lVACARMNo,L8EI20 INTRODUCTION a The -plain-flap type-of control device is being considered and incorporated in the design of high-epeed aircraft having swept wings. The design engineer on such aircraft is greatly wered, however, by a lack of data upon which to ba

7、ee estimates of the various lift and lateral-control design parametere. In order to help alleviate this difficulty, the National Ahis in pitch .- were detetined through a large athe effects of flap span and spsnwiee location on the values of lift ooefficient and pitching-mament coefficient obtained

8、on the subject wing with the sealed flaps deflected 30 are shown in the mmauxry figures presented as figures 12.and 13. Lift characteriatics.- The data pre8ented.i.n figures 7 to 10 end 12 show that increase in either the flap span or the flap deflection, within the range investigated, generally res

9、ulted in an increase in the lift at any given angle of attack andalso in the maximum lift obtainable. The incremental lift produced by unit flap deflection tended to decrease as the flap deflection or the angle of attack increased and was generally lerger at cc = O“ than at other angles of attack. T

10、he values of ACL obtained with the 0.52lg and 0.92% unseabd flaps deflected 60 were, respectively, at a = O“, approximately 0.33 and 0.43 approximately 0.29 and 0.35 at a = 12O, and approxi- mately 0.07 and 0.21 at Ck (figs. 7 and 10). The low value of A% shown here for the O-52$ flap as compared to

11、 the value of AC h for the 0.925$ flap has been noted previously in other investigations of partial-pan and full-span flaps on swept- back wings and is thought to be associated with a premature stall occurring over the inboard portion of the wing when a trailing- edge ,flap is deflected. This phenom

12、enon is more olesrly illustrated by a comparison of the lift curves of figures 7 to 9, which reveals that the values of ACD tend to decrease more rapidly for. inboard flaps than for outboard or full-span flaps, as the wing stall is approached. The decrease in the values of AC, produced by given flap

13、 deflections as a increased (figs. 7 to 10) wae also noted in the awept*ing investigation reported in reference 7; but was not noted in 4 . . t Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-EAC!ARMNo. I however, the reaulta of other Kind-tunnel inv

14、estigationa have indioated that the rate of increase of k uithRq-noldanmnber is less for sweptback winga than far unaweq-t wings in the critioel range of Reynolds number and is almost negligible when tramrition is fIxed on the wing leading edge. In addition to the increase in wing lift with flap apa

15、n previously noted, figures 8, 9, a (figs. 7 to 9). A comparison of the lift-drsg ratios L/a obtadned at the various flap deflections indicates that at valuea of k above aqproxtitely 0.6, a flap deflection of 30 provides almost the opt- value of L/D, and Ecrgr inoreaae Tn flap deflectIon does not Qq

16、move this ratio, although it does increase the lift coeffioient (ffg. 7). Because of the importance of the L/a ratio fortake4ffandlmding (aa well as for cruising flight), and beoauae of the increase in pitching mcment with flap deflection (as will be diaauased in the following section) it xtey be ad

17、vantageous to 1-t the flap defleotIon to a moderate value on aweptback wInga. See,lLng the flag produced no aignifioant changes in the ruluea of drag coefficient at given values of lift coefficient for a given percenti span flap (figs 7 and 8). Provided by IHSNot for ResaleNo reproduction or network

18、ing permitted without license from IHS-,-,-10 NACARMNo. Ithe subject wing had an .-table veriation of pitching-mamant coefficient tith lift coefficient regardless of the flap span, flap deflectian, or the ccnsdition of the flap-nose eeal (figs. 7 to 9). -ease in either the flap span or the flap defl

19、ection generally produced negative increment.6 of pitc-oment coefficient Aant ulues of a have been c-ted for each of the aileron arrangements investigated and are listed in table II. Beoauee the trends exhIbited by these values of total Cz for 8, = f30 are similar to the trenda exhfbited by the valu

20、ea of the aileroMffectiveneBs parameter Cz 8, for each of the aileron errangementer, anly the variatiorm of the parameter Cz8 with aileron a-pan, 6panu53e location, 8nd trailing edge angle will be de%t with in the foIlowIng discueaion of roll- moment c3haracteristice. The veriation of the ailero-ffe

21、ctiveneee param ter cz8* with the position of the lnboerd end of the aileron, for ailerons huving $I these valuee approximately correspond to the ge however, the ratio of yawing mment to rolling HlonleDlI w center- span aileron and the 0.!5!21b p inboard aileron as weI3 as for the O. however, this w

22、ould also limit the rolling power of the ailerons; which msy be serious at low speeds. In order to increase the deflection range of the ailerons above *O“, and thereby the available rolling moment, the size of the overhanging beJance,woe angle of 60 was modified by-cutting the inboard end of the ail

23、eron parallel to the plane of symmetry (fig. 4). A comparison of the data for the modified aileron configuration with that of the original aileron configura+.ion (figs. 24and 25 and table II) shows that the mod.ificat.ion resulted in *pproxima+.ely a *erGen+. reduction in the rolling power of the ai

24、leron, no this reduction amounted to approximately 55 percent in the value Of %a. Spoiler Control Chsracteriatice The aer oQ-nemic end lateral control charaoteristics of the wing equipped with the spoiler configuration shown in figure 6 and with the 0.92% unsealed flap deflected O“, 30, and 60 are s

25、hown in figure 26. As has been previously noted, the spoiler configuration wed for these teats is aimAlar to one of the more satisfactory configurations developed in the investigation reported in reference 8. A ccmperison of the aer odynemic characteristics of the flapped wing-spoiler configuration

26、with the characteristics of the plain flapped ning (fig. 7(b) f3h ows that the addition of the epoiler configuration on both semispens of the complete swept wing (for possible use as a epeed brake or a glideqath Control) generelly produced the ssme effects on the values of c In addition, the values

27、of C-D were increased, and the values of Cm and Ch generally became more positive (or less negative) at low angles of attack, and opposite trends were exhibited by these coefficients at large englee of attack. The spoiler configuration produced only small changes in the incremental values of CL, CD,

28、 Cm, and Ch resulting From deflection of the flap: The variation of spoiler-aileron roll- nt coefficient with angle of attack was irregular for sll three flap deflections; the values of Cz generally increased with increase in a at, values of a below approximately 14O Cb and (2% exhibited a slight sh

29、ift towerd more negative values as the aileron aman was increased toward the wing root section and as the spanwise location of a given span of aileron was moved inboard. In addition, for a given span of aileron, Ch and C% a exhibited lsrge changes toward less negative (or more positive) values as th

30、e aileron trailiWdg8 angle was increased. 6. Increase in the wing angle of attack had an inconsistent effect on the variation of seal-pressure coefficient with aileron deflection P8 a but generally produced a shift of the curves of the pressure coefficient against aileron deflection toward more posi

31、tive values of pressure coefficient. Increase in the aileron trailing-edge angle generally -7 = . resulted in slightly smaller values of Pg but had a negligible effect on the vsluee of pressure coefficient obta A = 3.43; taper ratio = 0.44. (All dimensions in feet, exept as noted.) 8 Provided by IHS

32、Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-. hssurrr &ads e- To munomafsr - - - kf Figure 2.- Location of pressure orifices on the semispan wing model. . t L . L Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-

33、. Figure 3.- The 51.30 sweptback semispan wing mounted near the ceiling in the Langley 330 MPH 7- by 10 -foot tunnel. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Fiu% 4.- Sketch of the 61. So sweptback semIspan wing showing the modified and origi

34、nal 0,404 i ailerons tasted. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-28 NACARMNo. L8HM - Ffgure 5.- Sketch of the flap and aileron contours tested on the 51.3O swepthack semispan wing model. (Contours and dimensions shown are in a plane normal to the ELI-percent-chord line of the wing in the unswept condition or approximately normal to the aileron hinge line.) c . .- Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-